.\" Copyright (c) 2010 Michael Kerrisk, <mtk.manpages@gmail.com>
.\"
.\" %%%LICENSE_START(VERBATIM)
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\" %%%LICENSE_END
.\"
.TH PTHREAD_SIGQUEUE 3 2021-03-22 "Linux" "Linux Programmer's Manual"
.SH NAME
pthread_sigqueue \- queue a signal and data to a thread
.SH SYNOPSIS
.nf
.B #include <signal.h>
.B #include <pthread.h>
.PP
.BI "int pthread_sigqueue(pthread_t " thread ", int " sig ,
.BI "                     const union sigval " value );
.fi
.PP
Compile and link with \fI\-pthread\fP.
.PP
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.PP
.BR pthread_sigqueue ():
.nf
    _GNU_SOURCE
.fi
.SH DESCRIPTION
The
.BR pthread_sigqueue ()
function performs a similar task to
.BR sigqueue (3),
but, rather than sending a signal to a process,
it sends a signal to a thread in the same process as the
calling thread.
.PP
The
.I thread
argument is the ID of a thread in the same process as the caller.
The
.I sig
argument specifies the signal to be sent.
The
.I value
argument specifies data to accompany the signal; see
.BR sigqueue (3)
for details.
.SH RETURN VALUE
On success,
.BR pthread_sigqueue ()
returns 0;
on error, it returns an error number.
.SH ERRORS
.TP
.B EAGAIN
The limit of signals which may be queued has been reached.
(See
.BR signal (7)
for further information.)
.TP
.B EINVAL
.I sig
was invalid.
.TP
.B ENOSYS
.BR pthread_sigqueue ()
is not supported on this system.
.TP
.B ESRCH
.I thread
is not valid.
.SH VERSIONS
The
.BR pthread_sigqueue ()
function first appeared in glibc 2.11.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.ad l
.nh
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.BR pthread_sigqueue ()
T}	Thread safety	MT-Safe
.TE
.hy
.ad
.sp 1
.SH CONFORMING TO
This function is a GNU extension.
.SH NOTES
The glibc implementation of
.BR pthread_sigqueue ()
gives an error
.RB ( EINVAL )
on attempts to send either of the real-time signals
used internally by the NPTL threading implementation.
See
.BR nptl (7)
for details.
.SH SEE ALSO
.BR rt_tgsigqueueinfo (2),
.BR sigaction (2),
.BR pthread_sigmask (3),
.BR sigqueue (3),
.BR sigwait (3),
.BR pthreads (7),
.BR signal (7)
.SH COLOPHON
This page is part of release 5.13 of the Linux
.I man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
\%https://www.kernel.org/doc/man\-pages/.
